With rapid development of science and technology and highly competitive market, performance and appearance of an electronic device is highly improved. Among others, notebook computers are becoming increasingly popular due to their advantages, such as compact size, portability, and high entertainment, and they have become an indispensible part in daily life. A user may have increasingly more things to do with a tablet computer having a communication function than ever. For example, with a tablet computer having a communication function, a user may communicate with others, watch videos, play games, or the like.
Currently, in order to have a correct system time in an electronic device, it usually requires an RTC (Real-Time Clock) battery, such as a button cell, provided for an RTC circuit in the electronic device. A clock frequency used for calculating time and energy used for storing time information and integrated circuit settings may be provided to the electronic device by this RTC battery, so as to guarantee a normal clock frequency for the electronic device. For example, if the notebook computer is in a switched-off state, with the separately provided button cell supplying power to the RTC circuit in the chip of the notebook computer, the system clock may be consistent with a standard clock when the notebook is turned on, and no manual operations of the user for setting the system time is required. In most cases, a button cell may keep supplying power to an RTC circuit for one year. However, due to the trend that an electronic device is becoming increasingly thinner and lighter, its internal space is becoming increasingly limited. An RTC battery that is dedicated to supply power to an RTC circuit will occupy the internal space of an electronic device, and therefore the difficulty in design as well as the cost for manufacturing the electronic device are increased.
Based thereon, it is a technical problem in the related art that the structure of an electronic device is complex.